Synthesis and curing of liquid crystalline epoxy resin based on asymmetric mesogen

A novel liquid crystalline epoxy resin (LCER) derived from asymmetric mesogen unit was synthesized. Its structure and liquid crystalline behavior were characterized by hydrogen nuclear magnetic resonance (H-NMR), differential scanning calorimetry (DSC), polarized optical microscopy (POM). The results indicated that the LCER converted to a nematic phase at 85 degrees C during heating and finally became isotropic at 145 degrees C. The curing behavior and phase behavior of the LCER with 4,4'-diaminodiphenyl methane and methyl hexahydrophthalic anhydride were also studied by DSC and POM, respectively. Their apparent activation energy (Ea) was evaluated according to the Ozawa's isoconversional method. The results suggested that autocatalytic reaction had occurred in these two systems. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012